Auxin Orchestrates Germ Cell Specification in Arabidopsis

The initiation and specification of germline cells are crucial for plant reproduction and the continuity of species. In Arabidopsis thaliana, auxin plays a vital role in guiding the transition of somatic cells into germline fate, orchestrating the specification of both male archesporial cells and female megaspore mother cells. This process is regulated through interaction with the transcription factor Sporocyteless/Nozzle, which forms a feedback mechanism that modulates germ cell specialization. Auxin biosynthesis, polar transport, and signal transduction pathways collectively ensure the accurate determination of germ cell fate. Furthermore, the coordination of auxin signaling with epigenetic regulation and miRNA-mediated control fine-tunes the differentiation between germline and somatic cells. This review discusses the mechanisms underlying auxin-guided germ cell specification. It proposes future research directions, including studies on PIN-FORMED-mediated polar transport, the role of the YUCCA family in auxin biosynthesis, and the involvement of the Transport Inhibitors Response 1/Auxn Signaling F-Box-Auxin Response Factor (TIR1/AFB-ARF) signaling pathway in germ cell fate determination. These insights will enhance our understanding of plant reproductive biology and provide new strategies for crop breeding.